A comprehensive RF safety concept for parallel
transmission MRI systems can be realized by verifying the SAR limits before
scanning and monitoring RF signals during scanning. However, using a
pre-calculated safety margin over-estimates the actual SAR. This abstract
extends the concept of pre-calculated safety margins with a real-time global
and local SAR monitoring system. This new concept allows for a significantly
increased permissible RF duty cycle and improves the detection of violations of
SAR limits or any unsafe condition. The impact of patient motion on SAR is
analyzed, and a scan termination in case of unsafe system operation is
demonstrated.